Weather Service Report


423 
FXUS66 KPQR 270354
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND 
854 PM PDT THU MAR 26 2015

.SYNOPSIS...HIGH PRESSURE WILL LEAD TO ANOTHER DAY WITH ABOVE 
AVERAGE TEMPERATURES AND SOME MORNING FOG IN THE LOWLANDS FRIDAY. 
HOWEVER...A FRONT WILL SPREAD RAIN SHOWERS INTO THE AREA LATE FRIDAY 
WITH POTENTIAL FOR THUNDERSTORMS NEAR THE CASCADE CREST. SHOWERS 
DIMINISH WITH A DRYING TREND ON SATURDAY. DRY AND MILD WEATHER LOOKS 
TO RETURN LATE SATURDAY THROUGH EARLY MONDAY. ANOTHER FRONT BRINGS 
MORE RAIN AND COOLER WEATHER TO THE AREA BEGINNING LATE MONDAY AND 
CONTINUES INTO THE MIDDLE OF NEXT WEEK. SNOW LEVELS WILL LIKELY DROP 
BELOW CASCADE PASS LEVELS DURING THIS PERIOD.

&&

.UPDATE...ONLY CHANGE WAS TO ADD PATCHY FOG BACK TO THE COAST AND 
COASTAL VALLEYS TONIGHT AS WEAK ONSHORE FLOW IS KEEPING DEW POINTS 
UP AND MUCH CLOSER TO THE FALLING TEMPERATURES. OTHERWISE...THE 
FORECAST REMAINS GENERALLY ON TRACK FRO THE REST OF TONIGHT AND 
TOMORROW. THUNDERSTORMS STILL SEEM PLAUSIBLE ALONG THE CASCADE CREST 
TOMORROW AFTERNOON AS INSTABILITY INCREASES AHEAD OF THE APPROACHING 
COLD FRONT. IT'S NOT A SLAM DUNK SCENARIO AND FEEL THAT THE 80 
PERCENT CHANCE OF IT NOT HAPPENING MIGHT BE A BETTER WAY TO SELL IT 
GIVEN INCREASING CLOUDS TO LIMIT SURFACE HEATING PLUS WEAK MID-LEVEL 
CAPPING. UPDATES WILL BE AVAILABLE SHORTLY. /JBONK

&&

.PREV DISC... /ISSUED 245 PM PDT THU MAR 26 2015/

SHORT TERM...TONIGHT THROUGH SUNDAY...VISIBLE SATELLITE IMAGERY 
INDICATES SUNNY SKIES ACROSS THE AREA WITH TEMPERATURES CLIMBING 
WELL INTO THE 60S. WITH A COUPLE MORE HOURS OF SOLID 
SUNSHINE...EXPECT MOST INTERIOR LOCATIONS TO WARM TO NEAR 70F. WITH 
MOSTLY CLEAR SKIES EXPECTED OVERNIGHT...EXPECT MORE LOWLAND FOG TO 
DEVELOP TONIGHT...BUT COVERAGE SHOULD BE A BIT LESS THAN THIS 
MORNING. 

A FRONT CURRENTLY POSITIONED BETWEEN 130W AND 140W WILL SHIFT TOWARD
THE REGION ON FRIDAY. LIFT AHEAD OF THE UPPER LEVEL TROUGH AND
COOLING TEMPERATURES ALOFT MAY INITIATE A FEW SHOWERS AND POSSIBLY A
THUNDERSTORM ACROSS THE CASCADES FRIDAY AFTERNOON. EXPECT THE BULK OF
THE SHOWERS ASSOCIATED WITH THE UPPER LEVEL TROUGH TO ARRIVE ACROSS
NORTHWEST OREGON AND SOUTHWEST WASHINGTON FRIDAY EVENING...LIKELY
CONTINUING FOR MUCH OF THE NIGHT. RAINFALL AMOUNTS SHOULD BE
RELATIVELY LIGHT...LIKELY LESS THAN A HALF INCH IN THE COAST RANGE
AND CASCADES...AND PROBABLY CLOSER TO A TENTH OR TWO TENTHS OF AN
INCH IN THE WILLAMETTE VALLEY. 

A LOWERING SUBSIDENCE INVERSION LATE FRIDAY NIGHT SHOULD RESULT IN
SHOWERS BECOMING INCREASINGLY CONFINED TO THE COAST AND CASCADES
BEFORE DECREASING FURTHER SATURDAY MORNING. A RELATIVELY FLAT RIDGE
SHOULD THEN BUILD INTO THE REGION LATE SATURDAY AND SUNDAY AND BRING
ANOTHER ROUND OF ABOVE AVERAGE TEMPERATURES. THIS SHOULD RESULT IN
GENERALLY DRY CONDITIONS ACROSS THE AREA. HOWEVER...MOISTURE
STREAMING NORTHEASTWARD ALONG THE EDGE OF THE HIGH PRESSURE WILL TAKE
AIM AT SOUTHWEST BRITISH COLUMBIA AND NORTHWEST WASHINGTON. AS A 
RESULT...THERE IS A CHANCE THIS RAIN COULD SHIFT BRIEFLY INTO FAR 
SOUTHWEST WASHINGTON DURING THIS PERIOD. IF NOTHING ELSE...LOW TO 
MID LEVEL CLOUDS WILL LIKELY BE A BIT MORE PERSISTENT ACROSS THE 
NORTHERN PORTION OF OUR CWA DURING THIS PERIOD. /NEUMAN


LONG TERM...SUN NIGHT THROUGH THU...OVERALL PATTERN REMAINS RATHER 
ZONAL...WITH WESTERLY FLOW ALOFT OVER THE REGION. THIS MEANS FRONTS 
WILL PUSH ACROSS THE REGION FROM TIME TO TIME...BUT NO SIGNIFICANTLY 
STRONG OR ORGANIZED SYSTEMS EXPECTED. AFTER A DRY PERIOD SAT NIGHT 
THROUGH SUN NIGHT...CLOUDS WILL INCREASE ON MON WITH ANOTHER ROUND 
OF RAIN FOR LATE IN THE DAY AND MON NIGHT. LIKELY SEE SHOWERS 
CONTINUE ON TUE AND TUE NIGHT AS COOLER AIR ALOFT PUSHES ACROSS 
REGION. AFTERWARDS...CONFIDENCE IN ANY SOLUTION BEGINS TO DROP AS 
MODELS DIVERGE ON ANY PARTICULAR SOLUTION. WILL TREND TOWARDS DRIER 
BUT KEEP SOME MINOR THREAT OF SHOWERS WITH NEAR SEASONABLE 
TEMPERATURES FOR SECOND HALF OF NEXT WEEK.   ROCKEY.


&&

.AVIATION...WITH HIGH PRESSURE...CLEAR SKIES...LIGHT WINDS...AND A
MOIST LOWER ATMOSPHERE...CONDITIONS ARE ONCE AGAIN RIPE FOR FOG
DEVELOPMENT. AS SUCH...EXPECT VFR CONDITIONS TO GIVE WAY TO
IFR/LIFR CIGS AND VSBYS AROUND MIDNIGHT. ONCE THE FOG
DEVELOPS...EXPECT IT TO REMAIN IN PLACE INTO TOMORROW MORNING
BEFORE LIFTING BY LATE MORNING. CONDITIONS WILL BRIEFLY RETURN TO
VFR TOMORROW AFTERNOON...BUT SLOWLY DETERIORATE TOWARDS MVFR BY
TOMORROW EVENING AS A COLD FRONT MOVES ACROSS THE REGION.

KPDX AND APPROACHES...VFR CONDITIONS WILL GIVE WAY TO IFR/LIFR
CIGS AND VSBYS AFTER MIDNIGHT AND REMAIN IN PLACE THROUGH TOMORROW
MORNING. CONDITIONS IMPROVE BACK TO VFR TOMORROW AFTERNOON...BUT
SHOULD SLOWLY DETERIORATE TOWARDS MVFR TOMORROW EVENING/NIGHT AS
A COLD FRONT MOVES ACROSS THE REGION. /64

&&

.MARINE...CALM WEATHER OVER THE WATERS WILL CONTINUE INTO TOMORROW
MORNING AS WEAK HIGH PRESSURE REMAINS OVER THE PACIFIC
NORTHWEST...WITH WINDS TO 10 KT AND SEAS HOVERING BETWEEN 7 AND 8
FT. A COLD FRONT WILL PUSH INTO THE WATERS TOMORROW AFTERNOON
ALLOWING WINDS TO INCREASE OUT OF THE SOUTH. WITH GUST TO 25 KT
EXPECTED TO DEVELOP OVER THE OUTER WATERS AHEAD OF THE FRONT DECIDED
TO ISSUE A SMALL CRAFT ADVISORY FOR TOMORROW AFTERNOON. WINDS OVER
THE INNER WATERS MAY BRIEFLY CLIMB ABOVE 21 KT...BUT DO NOT FEEL
THEY WILL LAST LONG ENOUGH OR BE WIDESPREAD TO WARRANT AN
ADVISORY. SEAS WILL LIKELY CLIMB A LITTLE WITH THE STRONGEST
WINDS...BUT SHOULD REMAIN BELOW 10 FT. /64

REMAINDER OF PREVIOUS DISCUSSION FOLLOWS...WEAK HIGH PRES RETURNS TO 
THE WATERS OVER THE WEEKEND. ANOTHER FRONT IS EXPECTED TO MOVE 
THROUGH ON MON. THIS FRONT LOOKS A LITTLE MORE IMPRESSIVE AND SHOULD 
BRING A SOLID ROUND OF SMALL CRAFT ADVISORY WINDS...WITH A SMALL 
CHANCE OF GALES. A MORE PROGRESSIVE WEATHER PATTERN FOR THE FIRST 
HALF OF NEXT WEEK. EXPECT SEAS TO REACH INTO THE LOW TEENS LATE SUN 
OR MON AND REMAIN ABOVE 10 FT FOR THE NEXT SEVERAL DAYS. PYLE

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 1 PM FRIDAY TO 3 AM PDT 
     SATURDAY FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD 
     OR FROM 10 TO 60 NM-WATERS FROM CASCADE HEAD TO FLORENCE OR 
     FROM 10 TO 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 9 AM 
     TO 1 PM PDT FRIDAY.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA     
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
 
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON 
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS 
COMMONLY REFERRED TO AS THE FORECAST AREA.

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